/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.dx.dex.file;

import com.android.dx.rop.cst.CstArray;
import com.android.dx.util.AnnotatedOutput;
import com.android.dx.util.ByteArrayAnnotatedOutput;

/**
 * Encoded array of constant values.
 */
public final class EncodedArrayItem extends OffsettedItem {

	/** the required alignment for instances of this class */
	private static final int ALIGNMENT = 1;

	/** {@code non-null;} the array to represent */
	private final CstArray array;

	/**
	 * {@code null-ok;} encoded form, ready for writing to a file; set during
	 * {@link #place0}
	 */
	private byte[] encodedForm;

	/**
	 * Constructs an instance.
	 * 
	 * @param array
	 *            {@code non-null;} array to represent
	 */
	public EncodedArrayItem(CstArray array) {
		/*
		 * The write size isn't known up-front because (the variable-lengthed)
		 * leb128 type is used to represent some things.
		 */
		super(ALIGNMENT, -1);

		if (array == null) {
			throw new NullPointerException("array == null");
		}

		this.array = array;
		this.encodedForm = null;
	}

	/** {@inheritDoc} */
	@Override
	public ItemType itemType() {
		return ItemType.TYPE_ENCODED_ARRAY_ITEM;
	}

	/** {@inheritDoc} */
	@Override
	public int hashCode() {
		return array.hashCode();
	}

	/** {@inheritDoc} */
	@Override
	protected int compareTo0(OffsettedItem other) {
		EncodedArrayItem otherArray = (EncodedArrayItem) other;

		return array.compareTo(otherArray.array);
	}

	/** {@inheritDoc} */
	@Override
	public String toHuman() {
		return array.toHuman();
	}

	/** {@inheritDoc} */
	public void addContents(DexFile file) {
		ValueEncoder.addContents(file, array);
	}

	/** {@inheritDoc} */
	@Override
	protected void place0(Section addedTo, int offset) {
		// Encode the data and note the size.

		ByteArrayAnnotatedOutput out = new ByteArrayAnnotatedOutput();
		ValueEncoder encoder = new ValueEncoder(addedTo.getFile(), out);

		encoder.writeArray(array, false);
		encodedForm = out.toByteArray();
		setWriteSize(encodedForm.length);
	}

	/** {@inheritDoc} */
	@Override
	protected void writeTo0(DexFile file, AnnotatedOutput out) {
		boolean annotates = out.annotates();

		if (annotates) {
			out.annotate(0, offsetString() + " encoded array");

			/*
			 * The output is to be annotated, so redo the work previously done
			 * by place0(), except this time annotations will actually get
			 * emitted.
			 */
			ValueEncoder encoder = new ValueEncoder(file, out);
			encoder.writeArray(array, true);
		} else {
			out.write(encodedForm);
		}
	}
}
